Courtesy of the Bath Short Story Award people:
To think about how to tighten your story in order to bring out its energy and subtle layers in a short space, this list of tips for writing short-short (or flash) fiction, from award winning poet, flash fiction writer, and writing tutor Mary-Jane Holmes, current judge of the Bath Flash Fiction Award, is very useful for all writers of short fiction.
Zoom in on a single event;
Begin in the middle of the action as close to the arc or climax of the story;
Decide where your focus is – event, point-of-view, character?;
Write using active voice and eliminate extraneous description;
Remember that every word counts;
Use a directive last sentence that gives narrative insight or opinion;
Make rereads necessary or at least inviting;
Close with a phrase that sends the reader back into the story;
Know when you’ve made your point.